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Hyperthreading and Houdini performance?

Posted: Tue May 10, 2011 6:06 am
by AnthonyTheSage
On the Houdini website its recommended to not use hyper threading. But if I set up the engine to use only one core, it responds by using only 50% of the processor. Since the processor is only a 1.66, half of that is not very good performance. I don't know much about processor architecture but is it possible to use the whole core for one thread? Or should I just set it to two cores? How can I get the best performance out of this weak processor? The processor is an intel atom n280 1.66 ghz. Any help would be appreciated, thanks.

Re: Hyperthreading and Houdini performance?

Posted: Tue May 10, 2011 8:00 am
by Uly
Go to engine options and switch Threads to 2 (this shouldn't be necessary as Houdini should auto-detect them, but also, you shouldn't be having that problem just by turning HT off).

Re: Hyperthreading and Houdini performance?

Posted: Tue May 10, 2011 6:24 pm
by hyatt
Uly wrote:Go to engine options and switch Threads to 2 (this shouldn't be necessary as Houdini should auto-detect them, but also, you shouldn't be having that problem just by turning HT off).

This is the wrong idea. If the CPU is a single core, with hyper-threading on, the O/S will see two processors. And many performance monitor tools will report that using 100% of one CPU is really 50% of total available processor power. On my 8-core boxes, when I use just one thread for debugging, "top" shows 12.5% cpu utilization:

Cpu(s): 12.7% us, 0.0% sy, 0.0% ni, 87.3% id, 0.0% wa, 0.0% hi, 0.0% si